Re: [Plplot-general] SVG driver patch

[Alan W. I. <ir...@be...>]

On 2013-02-14 16:19+0800 Joseph Wang wrote:

> FYI,
>
> I just submitted a patch to the SVG driver on the sourceforge project
> page.  The patch
> moves some of the transforms into the text element itself and it cuts
> down the size
> of the SVG by 50% in some of my test cases.  What happens is that the SVG driver
> uses text to plots out hershey fonts, so you have data heavy plots in
> which each point
> is a massive bit of XML.

Hi Joseph:

Thanks for your patch, but before looking at it in any detail I would
appreciate some clarification of the explanation you made above
about the reduction in size of the resulting SVG.

I haven't looked at the svg code in a while, but I am virtually
positive it does not use Hershey fonts. For example, I just took a
quick look at some -dev svg results, and it appears that by default it
is using generic fonts, i.e., sans-serif, serif, etc., rather that
specific font choices.  So specific font choice becomes (by design)
the responsibility of the svg viewer, and has nothing to do with
PLplot and especially our old-fashioned Hershey fonts.

If it turns out I am wrong, and there are cases where it is possible
for -dev svg to use Hershey fonts, I think that is a bug that should
be fixed.

If I am right, then there must be some other explanation of why you
have been able to achieve reductions in svg result sizes by a factor
of two in some cases with your patch.  That's obviously an outstanding
result that I think we should incorporate, but it would be good to
get a clear explanation as to why your patch reduces result size so
much.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
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